Jockey wheel blues?

[Buckman]

Some people with twin axle caravans have complained about issues with jockey wheel. I am wondering if the problem is because of the huge strains or pressures that are imposed on the assembly causing the clamp to distort resulting in the caravan dropping down the jockey wheel shaft?
Would make any difference if the jockey wheel was used to lift the front of the caravan as much as possible without having the assembly at its extreme.
This in turn will lift the wheels on the front axle creating less resistance of the tyres on the ground when turning and making it easier to turn the caravan. Also there will be a lot less pressure on the jockey wheel assembly and less strain on the clamp.
Not being an engineer I have no idea if this will help prevent issue with jockey wheel assemblies. Ours is a 2018 Cruiser nearly 4 years old and we have had no issues with the jockey wheel assembly.
Any thoughts from engineer type posters?

 

[Raywood]

Raising the front wheels of the ground would reduce the drag particularly on gravel pitches when turning and might increase the life of the jockey wheel if moving by hand. Most people have a motor fitted, though so that would normally require the front wheels down. Given the weight of most twin axle models, I doubt many people move them by hand.

 

[Thingy]

Raising the front of the caravan to lift the axle will put more weight on the nose, but will put less scrub on the tyres on the axle. Whether one or two axles on the ground wont make any difference to the turning pressures at the front.

 

[ProfJohnL]

The problem of turning TA's especially by hand is the tyre scrub. During any turning manoeuvre at least two wheels of a TA have to move sideways rather than just roll.

It is certainly true that by raising or lowering the jockey wheel it will adjust the relative pressure on each wheel, because of the limited range of height adjustment on the jockey wheel compared to the distance between the JW and the axles, and the compliance of the suspension and tyres, the amount of load transfer from one axle to the other is not a great deal and less so on longer caravans. So whilst every little helps. in practice it doesn't make a big difference.

As with measuring nose load on a TA where only a relatively small difference in hitch height can result in a much bigger change in teh applied load than compared to an SA, the JW will also experience a similar change in load for the same reason. This makes the JW on a TA potentialy carry a lot more load than compared to an SA of similar size.

The above coupled to the natural tendency of a TA to want to try stay rolling in a straight line and any unevenness in surface may try to deviate the JW, which the chassis resists putting the JW clamp under greater strain.

 

[Buckman]

The caravan has AWD motor mover and nose weight is about 140kg. I was also thinking of tyre scrub when turning sharply something that is not required too often, but if doing it on grass, it rips up the grass. Just looking at making the impact less which is why I thought of lifting the front, but have concerns about strain on jocket wheel assembly and clamp.